The thin film transistor liquid crystal display (TFT-LCD) is widely used in consumer electronics such as television, computer, mobile phone and the like. Usually, the TFT-LCD comprises a liquid crystal panel having pixel units arranged in a matrix, wherein the driving circuit is provided to drive the pixel units to display.
FIG. 1 schematically illustrates a circuit block diagram of a typical TFT-LCD. Referring to FIG. 1, the TFT-LCD device comprises a liquid crystal panel having m×n pixel units arranged in a matrix, m source lines (also called data lines) S1 to Sm and n gate lines G1 to Gn which are intersected with each other and thin film transistors arranged at points where the data lines and the gate lines intersect, source drivers for providing data to the data lines S1 to Sm of the liquid crystal panel, and gate drivers for providing scan pulses to the gate lines G1 to Gn. The gate drivers outputs, in response to a clock signal, the scan pulses on the gate lines G1, G2, . . . Gn (also called scan lines) successively to control turning-on and turning-off of the TFTs on respective gate lines, and the source drivers converts the display data into gray-scale voltages when the TFTs are turned on, so as to charge the pixel units to enable display of data.
The TFT-LCD currently develops towards large size and high resolution. Since the large size of the panel would lead to large RC of the gate lines and the common electrode lines, if there is a large difference between display data (i.e. gray-scale voltages) in two adjacent rows, it would cause the loading capacity of the source driver to be insufficient. Moreover, the VCOM voltage would be affected due to a sudden change in the gray-scale voltages such that the voltage applied on the pixel units is instable. These always result in unfavorable display effects such as artifact and crosstalk.
Therefore, there is a demand for an improved source driver and corresponding driving circuit and driving method for the TFT-LCD.